Learning Forum

[KarenSthefany28]

My mesh is 30 mm for the wall, 50 mm for the base and 30 mm for the reinforcement (which was modeled using beam in SpaceClaim) then turned into "reinforcement" in Mechanical, model type. I need big elements because I use a student version (I'm using 106K/128K available nodes).

The simulation is non-linear, I applied a fixed support under the lower face of the wall's base. There's one contact region, I used "bonded". I'm obtaining the following errors...

ERRORS:

-Probe is displaying an unconverged solution

-An unknown error occurred during solution. Check the Solver Output on the Solution Information object for possible causes.

-The solution failed to solve completely at all time points. Restart points are available to continue the analysis.

-Large deformation effects are active which may have invalidated some of your applied supports such as displacement, cylindrical, frictionless, or compression only. Refer to Troubleshooting in the Help System for more details.

-Although the solution failed to solve completely at all time points, partial results at some points have been able to be solved. Refer to Troubleshooting in the Help System for more details.

-The unconverged solution (identified as Substep 999999) is output for analysis debug purposes. Results at this time should not be used for any other purpose.

Please, somebody help me. Have a nice day

[Manish Dubey]

The errors you are seeing because your model has failed to converge. There are quite a few things that could be checked in the model.
i) Is your mesh sufficient and are the loads you are applying reasonable in respect to the timesteps you are asking for?
ii) Check the initial status of all your contacts (using Contact Tool) and that the definition matches up with your expectations.
iii) Ask for Newton Raphson residuals (under Solution Information). This can sometimes be a useful tool to help diagnose where the problem lies.
Going through all of this may help you to understand why the solver struggling to converge.
Thanks
Manish

[KarenSthefany28]

Dear Manish Thank you so much for your reply!!
In my non-expert opinion my mesh seems sufficient, symmetric, and very uniform, I instantly assume that's not it. I'm not sure how to make a reasonable "displacement controlled" test with respect to the timesteps. I'm applying a 100 mm displacement and I've tried different combos (60mm, 70mm, 80mm, 90mm) with substeps (initial, min, max: 20, 20, 100 - 200, 200, 1000- 5, 5, 10, etc ...) And it still doesn't seem to converge.
Unfortunately, I'm not 100% sure how to interpret the NR residuals. Again, thank you so much for taking the time to answer my question, any further information you could provide on the topics I just commented on will be highly appreciated! ;)
-NR residuals and displacement/substeps.
Best Karen